Conscious sedation with remifentanil during painful medical procedures

Remifentanil, a recently introduced ultra-short acting opioid, was used as a component of a conscious sedation technique in 30 patients for 40 painful medical procedures. In 31 of these procedures, remifentanil provided sufficient analgesia. However 25 of those 31 patients developed apnea that required constant verbal stimulation at doses equal to or less than the dose required for analgesia. Ten of these apneic patients developed hypoxemia (oxyhemoglobin saturation less than 90%). Nine patients required abandonment of remifentanil and addition of either ketamine or propofol to achieve an analgesic state without respiratory depression. Although discharge times with remifentanil were considerably shorter most patients, parents, and practitioners were not satisfied with the technique because of the prolonged time to reach an analgesic state, and their fear of persistent apnea. Therefore, remifentanil is generally not a useful agent as part of a conscious sedation technique during brief painful procedures. Although discharge times are rapid it is accompanied by a high incidence of life-threatening respiratory depression at subtherapeutic levels. (C) U.S. Cancer Pain Relief Committee, 2000.